Field of the Invention
The present invention relates to a stage apparatus, a lithography apparatus, a method of manufacturing an article, and a determination method.
Description of the Related Art
With lithography apparatuses used in manufacturing semiconductor devices and the like, it has been desired that a stage that holds a substrate or a mask is positioned with high accuracy. Generally, in lithography apparatuses, a driving unit that drives a stage by providing thrust to the stage is provided, and the position of the stage is controlled by supplying a signal (first signal) for reducing deviation between the current position and a target position of the stage to the driving unit.
With a lithography apparatus having this kind of configuration, it is known that a ripple (thrust ripple) is included in the thrust supplied by the driving unit to the stage, and the thrust ripple causes the stage to vibrate. Japanese Patent Laid-Open No. 2001-175332 and Japanese Patent Laid-Open No. 2003-88159 propose a method of controlling the position of a stage by supplying a first signal and a signal (second signal) for reducing vibration of the stage that is caused by thrust ripple to the driving unit. Japanese Patent Laid-Open No. 2001-175332 discloses a method of obtaining a thrust ripple based on a model formula using the design data for the driving unit (e.g., a linear motor) and determining the second signal so as to cancel out the obtained thrust ripple. Also, Japanese Patent Laid-Open No. 2003-88159 discloses a method in which the second signal is determined with a focus on the fact that the frequency of the thrust ripple is an integer multiple of the electrical angular frequency of a motor included in the driving unit.
As with the method disclosed in Japanese Patent Laid-Open No. 2001-175332, vibration of the stage caused by the thrust ripple may not be sufficiently reduced if the second signal is determined based only on the thrust ripple obtained based on the model formula using the design data of the driving unit. Also, in Japanese Patent Laid-Open No. 2003-88159, it is not disclosed that the amplitude and phase of the second signal are determined so as to reduce vibration of the stage caused by the thrust ripple.